Laminated spring



July 14, 1931. A. E. FROST 1,814,682

LAMINATED SPRING Filed Aug. 14, 1929 2 sheets-sheet 1 Jr-warum' HRTHUR ERNEST FROST:

ATTORNEYS July 14, 1931. A. E. FRs'r LAMINATED SPRING h Filed Aug. 14, zsheets-shez 2 Jfwawbr/ ARTHUR ERNEST FROST,

ATTORNEY:

0 the quarter-elliptic type Patented July '14,' 1931 i ARTHUR EnNEs'r FROST,

E SHEEEIELD, ENGLAND LAMINATED SPRING- Appncation lea'nugust 14, ieaasefiizno so called by reason of it constituting the main member by which the whole springfrelies for its suspension or support in use. V i In mounting laminated springs it A'is essential that some means be provided at the ends for connecting the spring to the vehicle and inthe semi-elliptic type of spring each end is usuallyl connectedv tothe vehicle and the centreV is connectedto the axle, whilst in of spring one end is connected to the vehicle and the other end totheaxle.

' The methodusually adopted in connecting that end of the spring which is connected to the vehicle `as distinct from the axle, is to provide the main leaf with a form of end or ends adapated to accommodate a pin, and

provided with suitable means for such attachment to the vehicle, or in some cases one end of the'main leaf is slidably accommodated in a housing or frameattached to the vehicle.

This master leaf, therefore, functions with the remainder of the leaves and issubjected to bending stressesin addition tol-'taking the stresses imposed by transmission of the vehicle. L

In designing, a'laminated' spring an endeavour is made to y.provide a main leaf strong enough to withstand this"dual task, but a compromise has to be made in determining the thickness of the leaf, as on the one hand it must be. thick enough j to withstand A,the

forces imposed by transmissiom whilst on the other hand it must be thin enough to keep down the stress due to flexion within a margin of safety; As a result, therefore, Vof this compromise, ythe strengthy of the main leaf is limited, but with a view to somewhat i j strengthening'V 1t, one or more yadditional 'i "5 leaves, known as re-bound plates have been d-for the suspenl Y n or master leaf, or as it is some- 10 times termed, the back plate or top plate7 is 385,829, arid in Great' Britain April e, 1929.

introduced adjacent the main leaf inorder to reinforce it, whilstin some cases the master leaf has been formed of two partssuitably coupled at the centre. j

In the methods adopted', therefore, the feature that the master leaf should be subject to bending stresses due to iiexion as welly as to stresses dueto transmission is commonA to prevent failure or breakage have failed, for it is obvious that under such conditions fthe whole spring is only as strong as the weakness v of the master leaf to fulfill its dual purpose. By this invention it is sought to provide lmprovements which will overcome thefailures and breakages above-mentioned, and to this end, therefore, a laminated spring is pro,- yvided with an extensible and contractible supportingv or suspension Vmember or platel that is not subjected to the usual bending stresses on the 'flexion of the spring, yety flexibly accommodates itself to and assimilates the curvature of the spring.

A spring made according to this invention, therefore, ycomprises a plurality of laminations wherein the supporting or suspending means comprises an articulated or disjointed member disposed within the laminations so arranged and adapted as to nonresiliently accommodate itself to the varying 'curvature of the laminations under stress.

. Preferably the member or plate comprises a plurality of elements movably connected with one another and accommodated between two adjacent leaves or laminas of an assembled spring, vsaid elements being capable of individual and combined movement so as to accommodate themselves to them all, and for this reasonall attempts to 'curvaturer .of the springy under stress, ex-

posed ende of saidmember being adapted, or provided with means, for connection to a vehicle. At least one of saidelements may be adapted, where desired, for connection to the assembled spring or a leaf thereof. Further, one of the elements may also be adapted or provided with means for securing it to the axle. v n

Further still, one of the elements may be adapted or 'ded with means, for con- Y prov1 j Sttuting or :forming part of the buckle or other fastening for connecting the several leaves or laminas of the spring together.

The elements are, or may be so formed or provided with means for preventing other than designed displacement. They may be flat, arcuate, or other convenient shape accord` ing to requirements, andV of any siutable metalY or material".

`Where convenient or desirable, the elements may be connected by the introduction of a separate unitzorunits,` andithe jointsV forming the coupling may be of rounded form resembling a ball joint. Y

Further, more than one connection between each pair of elements may be providedand saidconnectionfor connectionssmay be of substantialfly the same. thicknessA as' the elements, orfofa difil'erentthiclness.,

The invention will be betterl understood on:- referenceto/the.. accompanying sheets of Idrawings in; which Fi'gql isanheleuation. of one form of, suspensionunember .made accordance with this ,invention vandshown. in itsfuflly contracted, position,-`

F ig.,2; is aplanof same.;

Fig). 3, 's a similar View to. Fig.. .1,.but-showing the, suspension member inits extended position.; and. Y Y

Figr is aplan of same Fig. 5.is` an elevation of., anassembled semielliptic. spring embodying. the, fonmof. suspension member depicted. in Figstlv toll, the springA and suspension member being shown inrthe. normal position Fig. 6 isanelevation illustrating thespring shown in'Fig ..5 attened out: under stress;

Fig. 7 is an elevation of a. spring embodying a modified form of suspension member;

Fig. 8 isa plan of same.;

Fig. 9.isya.section on the line A-lvFig.` 7.

The form: of suspension member depicted 1 compnises a plurality of: separate elements a,

acapableiof ,beingcoupled together as shown by a lug on .oney elementv engaging aV slot c inan. adjacenty element in such ka manner that although `said elements. cannot-be pulled completely, apart .longitudinally they canA be pulled slightly apart to 1p ermitfofextensibility of themember as seen. in Figs.f3 and 4, the two.-.end. elements beingtormedwith an eye d for the receptionof the usual pin provided on aD vehicle fon suspending a1. spring.V

In use, thearticulated'. suspension member is accommodated` in asimilar manner to the usual master leafv between two adj acentleaves or laminae e of a. spring as shown in Figs. 5 m8., and adaptsitselftothe curvaturetheneof, lthe several laminzefbeing held. together in any Wellknoivn manner, asv for example by the usual shackles g which. are. securedby boltsft passingrthrough eyes jformed at the ends .ostl someof. therlaminlae asshown'in Figs. 5 and. 6., the; springbeing mounted. on. pins out. necessitatingfthe usual pre-,heating ofthe (not seen) passing through the eyes (l of the end elements. rIhe centre element a is, or may be connected along With the remaining laminae e to an axle in any convenient manner.

In use, when the spring f is not under stress, the articulated ymember `is extended when employed in thesemi-elliptic type of spring as illustrated, and on the spring f fiatte'ni'ng out under load or shock, the elements a close. on. to one anotherwhereby the articulated member assumes a contracted length Whilst'- adapting itself to the alteration in curvature of the spring. On re-action of the spring f the elements a open again.

, It Wil-l, therefore, be; seen ,that the. s -ring )f can be mounted, if desiredyaboiitixe centres.

It Will also be seen Ghatowing to ythe extensibility and contractibility of the, articulated member inI adapting itself Vto thevarying curvature Aofthe spring', said member isf free trom the bending stresses t0 which; thefusual 4master leaf is subjected. and has. onlythe lhorizontal forces, to contendV with.. The re maining v1leaves: or laminae `of thez springlare, therefore, permitted to. function more-easily with the resultthatthe, stresses to which the spring: isr` subjected. aref more evenly distributed..

It is to be understood.thattheelements o may be. ofY any suitablerorm. and although they are in the examples illustrated shown as* straight pieces theymay. be.; arcuate. or other convenient. shapeas desired. f K Y Further, the connection of one. element with another may be of any suitable form other: than that. illustrated. andifthe ext-ent Vof:movement betweenrthe. elements may var.)7 according tothevconditions met with..

Lateral displacementbf. the elements. is prevent-ed` by thevform. oi connections het\veen. them,A but other, means, may` be7 employed'for. the same purpos.efor example the elements may h aver sli dahle, engagement Ywith ;1

an adjacentrleafofthefspringa Also any. of theelements beprovided with: lugs or. otherwise adapted for the attachment` or accommodation of the shackles orl other. fastenings and the, end elements;

maybe of any shape adaptable for mounting thespring inimy desiredrand convenient manner.,

Inr Figs. '7*.8and, 9, isiillustrated arspring `embodying a,.:modied form of articulated suspension: membeninl that: vthecentne elementmisformed integral Wit-hi the buckle lc, thus permitting thespring andbuckle to he securelyv attache-de and.l bound together Withbuclrle and attachment. under hydrilllll'il pressure, and.. thereby. eliminating .the vdanger of nialforniationof.machinedldimensions. Also some; ofthe.. elements are notched.alongwith thefother leaifes fefltheisplg as. Shown at m l roo for accommodating engaging sides of the shackles g, the bolt heads .and nuts Ain the plan, Fig. 8 being omitted.

It is also to be understood. that this invention is applicable to all or most types of laminated springs and including the straight type and the quarter-elliptic type of spring.

lVhat l claim and desire to secure by Letters Patent is l. A laminated spring comprising a plurality of laminations wherein the supporting or suspending means comprises an articulatedmember disposed withinthe lamnations so arranged and adaptedas to accommodate itself to the varying curvature oi the laminations under stress, said articulated member being bound together with the laminations. Y

2. A laminated spring comprising a plu-y rality of laminations wherein the supporting or suspending means comprises an articulated member disposed within ythe laminations so arranged and adapted as to accommodate itself tothe varying curvature of the laminations understress, and means for embracing said articulatedmember and the laminations.

3. For a laminated spring, an articulated suspension member comprising a plurality of element-s movably connected one to another to create extensibility and contractibility in said articulated suspension member, extreme elements being adapted for connection to a vehicle.

4. For a laminated spring, an articulated suspension member comprising a pluralityof elements movably connected one to another to create extensibility and contractibility in said articulated suspension member7 said elements being connected by a tongue and slot engagement of one with another, extreme elements being adapted for connection to a vehicle.

5. A laminated spring comprising a plurality of laminations wherein the supporting or suspending means comprises an articulated member so arranged as to non-resiliently accommodate itself to the varying curvature of the laminationsunder stress, said articulated member comprising a plurality of elements so coupled one to another in a single line as to be capable of relative movement to give extensibility and contractibility in the member.

6. A laminated spring comprising a plurality of laminations wherein the supporting or suspending means comprises an articulated member so arranged as to non-resiliently accommodate itself to the varying curvature of the laminations under stress, said articulated member comprising a plurality of elements so coupled one to another in a single line as to be capable of relative movement to give extensibility and contractibility in the member, and means for embracing said suspension member and the laminations.

7 A laminated spring comprising a plurality of laminations wherein the supporting or suspending means comprises an articulated member so arranged as to non-resiliently accommodate itself to the varying curva ture of the laminations under stress, said articulated member comprising a plurality of elements so coupled one to another in a single line as to be capable of relative movement to give extensibility and contractibility in the member, and means for embracing said articulated member and the laminations, said means being integrally combined with said articulated member.

In testimony whereof, I affix my signature. f ARTHUR E. FROST.

llt) 

